Genetic Screening

• What is genetic screening used for?

  To determine specific alleles in the genome
• When might genetic screening be required?

  In older pregnancies or with family history
• What are the three methods of genetic screening?

  1. Identifying carriers for a disorder
  2. Pre-implantation genetic diagnosis (PGD)
  3. Pre-natal testing
• What is the purpose of identifying carriers for a disorder?

  To see if they have the disorder allele
• How can a couple use carrier testing results?

  To make informed pregnancy decisions
• What are potential issues with genetic screening?

  False positives/negatives and emotional stress
• What is pre-implantation genetic diagnosis (PGD)?


  Testing embryos for genetic disorders before implantation
• How does PGD help couples during IVF?

  It allows them to choose healthy embryos
• What ethical concerns are associated with PGD?

  Potential for 'designer babies' and embryo discarding
• What is chorionic villus sampling (CVS)?

  A prenatal test for genetic disorders
• When is chorionic villus sampling typically performed?

  Between 11-14 weeks of pregnancy
• What is the risk of miscarriage associated with CVS?

  1-2% risk of miscarriage
• What type of cells are obtained during CVS?

  Fetal cells from the placenta
• What is amniocentesis?

  A prenatal test for genetic disorders
• When is amniocentesis typically performed?

  Between 15-20 weeks of pregnancy
• What is the risk of miscarriage associated with amniocentesis?

  1% risk of miscarriage
• What is a potential issue with the timing of amniocentesis results?

  Results take time, causing trauma
• What are the ethical issues related to prenatal screening?

  Decisions to abort based on results
• What is pre-natal screening?

  Testing for genetic disorders before birth
• What are the two types of pre-natal screening?

  Chorionic villus sampling and amniocentesis
• Which couples would typically undergo pre-natal screening?

  Those with a family history of genetic disorders
• What is miscarriage?

  The loss of a fetus before 20 weeks
• How is prenatal testing performed?

  By obtaining fetal cells from the placenta or fluid
• What prenatal test can detect Tay-Sachs disease at 11 weeks?

  Chorionic villus sampling (CVS)
• Why might a couple choose not to have CVS?

  Concerns about miscarriage risk and ethical issues